The present invention relates generally to film wrapping apparatus, and a method for performing the same with respect to palletized loads or products, and more particularly to a new and improved film wrapping apparatus or system which is truly portable and readily enables the manual wrapping of palletized loads or products with wrapping film.
As has been noted within previously filed U.S. patent application Ser. No. 09/432,284, which was filed on Nov. 2, 1999 and in the name of Hugh J. Zentmyer et al. for an APPARATUS AND METHOD FOR MANUALLY APPLYING STRETCH FILM TO PALLETIZED PRODUCTS, it is a known fact that approximately fifty per-cent (50%) of all stretch film that is manufactured is applied to, for example, palletized loads or products by manual means. It is also known that when applying such stretch film to, for example, palletized loads or products, the manner in which such stretch film is manually applied to such loads or products usually comprises either one of two methods. In accordance with a first one of such manual methods, as illustrated, for example, within U.S. Pat. No. 5,398,884 which issued to Stanford on Mar. 21, 1995, the operator respectively inserts four fingers of each hand into each one of two oppositely disposed recessed portions defined within the film core end caps so as to effectively hold or grasp the film roll, and while placing his thumbs upon outside surface portions of the film roll, so as to effectively cause a predetermined amount of back tension to be applied to the film whereby the film is effectively stretched as the film is being unrolled or dispensed from the film roll, the operator walks around the palletized load or product. In accordance with a second one of such manual methods of applying a stretch film to such palletized loads or products, as illustrated, for example, within U.S. Pat. No. 5,458,841 which issued to Shirrell on Oct. 17, 1995, and in lieu of directly holding or grasping the film roll, the operator holds or grasps a film roll dispensing or holding device which has a built-in tensioning mechanism.
In accordance with either one of the aforenoted modes, methods, or manners in which stretch film is applied manually to the palletized products or loads, several operational disadvantages or drawbacks common to both methods or modes were apparent. Firstly, for example, the film roll, or the film roll and film roll dispensing or holding device, must be supported by the operator personnel, and yet the film roll and the film roll dispensing or holding device are quite heavy and cumbersome. In addition, in order to fully wrap a palletized load, the operator must bend down while holding the film roll, or the film roll and film roll dispensing or holding device, in order to wrap the film around the lower extremity portions of the palletized loads or products. Such requirements upon the operator personnel have been noted to cause acute discomfort, fatigue, and stress-related injuries. In addition, the operators experience fatigue and discomfort even when the operators are wrapping the upper regions of the palletized loads or products due to the continuous need for supporting the entire weight of the film roll, or the film roll and film roll dispensing or holding device.
A need therefore existed in the art for an apparatus, and for a method of operating the same, for overcoming the various operational disadvantages or drawbacks characteristic of the known PRIOR ART systems as briefly discussed hereinbefore and as disclosed within the aforenoted patents, and this need was substantially met by means of the apparatus or system, and the method of operating the same, which has been disclosed within the aforenoted U.S. patent application Ser. No. 09/432,284 and which has been quite commercially successful. However, while it has been noted in such aforenoted patent application that the apparatus or system disclosed within the aforenoted U.S. patent application Ser. No. 09/432,284 is portable in that the same is mounted upon a platform which has wheels, rollers, or the like so as to render the same movable or mobile, the apparatus is nevertheless relatively large and not readily transportable so as to, in turn, not be readily or easily movable within a particular wrapping plant or facility, or even yet further, readily or easily transportable between different wrapping plants or facilities located at different production sites.
A need therefore exists in the art for a new and improved film wrapping apparatus wherein the film wrapping apparatus is truly portable and transportable so as to readily enable the manual wrapping of palletized loads or products with wrapping film at a particular location within a production facility, at different locations within a particular production facility, or at different production facilities.
Accordingly, it is an object of the present invention to provide a new and improved apparatus or system for applying wrapping film to palletized loads or products.
Another object of the present invention is to provide a new and improved apparatus or system for applying wrapping film to palletized loads or products wherein the various operational drawbacks and disadvantages, characteristic of PRIOR ART apparatus, systems, or methods of operating the same, are overcome.
An additional object of the present invention is to provide a new and improved apparatus or system for applying wrapping film to palletized loads or products wherein the wrapping film can be applied to or wrapped around the palletized loads or products by means of operator personnel who can simply walk around the pallet upon which the loads or products are disposed and simultaneously push or guide the roll of wrapping film around the palletized loads or products whereby the palletized loads or products are accordingly packaged with such wrapping film.
A further object of the present invention is to provide a new and improved apparatus or system for applying packaging film to palletized loads or products wherein the packaging film can be applied to or wrapped around the entire vertical extent of the palletized loads or products by means of operator personnel who need not support the weight of the film roll, or the film roll and the film roll dispensing mechanism, and in addition need not bend down in order to wrap or apply the stretch film upon or to the lower extremity portions of the palletized loads or products.
A still yet further object of the present invention is to provide a new and improved apparatus or system for applying packaging film to palletized loads or products wherein the film wrapping apparatus or system is truly portable and transportable so as to readily enable the manual wrapping of palletized loads or products with wrapping film at a particular location within a production facility, at different locations within a particular production facility, or at different production facilities.
The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved portable film wrapping apparatus or system which comprises, in effect, a manually movable cart which is formed by means of a chassis wherein a pair of relatively large non-pivotal or non-caster type wheels are mounted upon a rear end portion of the chassis while a pair of relatively small pivotal or caster-type wheels are mounted upon a front end portion of the chassis. The pair of relatively large rear wheels are mounted upon an axle in such a manner that one of the relatively large rear wheels is fixed upon the axle, while the other one of the relatively large rear wheels is freely rotatable upon the axle, and in this manner, the first relatively large rear wheel serves as a drive wheel to drive the axle. A drive sprocket is also mounted, through means of a one-way clutch mechanism, upon the axle on which the large drive wheel is mounted such that when the drive wheel is rotated in a forward direction, rotational drive is transmitted to the drive sprocket, whereas conversely, when the drive wheel is rotated in the backward or reverse direction, rotational drive is not transmitted to the drive sprocket. A lift drum bridge is mounted upon a relatively central portion of the chassis, and a clutch shaft is fixedly mounted upon the lift drum bridge. A lift sprocket is rotatably mounted upon the clutch shaft and is operatively connected to the drive sprocket by means of a drive chain. A lift drum is also mounted upon the clutch shaft and is spring-biased into contact with the lift sprocket by means of a pin-and-hole clutch mechanism defined between the lift drum and the lift sprocket such that when the clutch mechanism is engaged, the lift drum is rotated by means of the lift sprocket. A lift cable is connected at one end thereof to the lift drum so as to be wrapped around the lift drum as the system cart is manually maneuvered, along a circular locus around a load to be packaged in wrapping film, by means of an operator, and the other end of the lift cable is attached to a film roll carriage which is vertically movable along a track defined upon an upstanding mast and upon which a roll of wrapping film is mounted.
Accordingly, as the operator continuously maneuvers the system cart around the load to be packaged in wrapping film, rotation of the large drive wheel causes rotation of the drive sprocket which in turn causes rotation of the lift sprocket and the lift drum. Consequently, the lift cable is wrapped around the lift drum and the film roll carriage is elevated so as to continuously enable dispensing of the packaging film and wrapping of the same around the entire vertical extent of the load being wrapped in a spiral wrap mode. If continuous or concentric wrapping of the load with the packaging film at a particular elevational level is desired, which is known as reinforcing wrapping, the lift drum is operatively disengaged from the lift sprocket such that the lift drum is no longer rotated and the lift cable is not wound any further upon the lift drum. The system further comprises a spring-biased, one-way pawl mechanism which is pivotally movable with respect to the lift cable so as to permit the lift cable to be wound upon the lift drum during elevation of the film roll carriage attendant a film wrapping operation. However, conversely, the one-way pawl mechanism is biased into engagement with the lift cable in order to prevent the cable from unwinding with respect to the lift drum so as to in turn prevent the film roll carriage from descending when such descent is not desired, such as, for example, when the cart is not being moved, when the cart is being moved in a reverse direction, when the cart is being moved during the performance of a reinforcing wrap operation, or when the cart is being moved along the ground or floor of a facility so as to be transported between different packaging or wrapping locations.
In order to in fact permit the film roll carriage to descend, such as, for example, upon the completion of a particular load wrapping operation and in order to prepare for the initiation of a new wrapping operation with respect to a new load to be wrapped, the one-way pawl is adapted to be disengaged from the lift cable such that the cable is in fact free to unwind from, or with respect to, the lift drum. In conjunction with the disengagement of the one-way pawl mechanism, a jack lever is also operated so as to elevate the large drive wheel with respect to the ground or floor and thereby disengage the same from its contact with the ground or floor of the wrapping facility or plant. In this manner, reverse rotation of the lift drum, through means of the rotation of the lift sprocket, the drive sprocket, and the large drive wheel, is permitted or facilitated such that descent of the film roll carriage is then permitted in a predeterminedly controlled manner as defined or determined by means of the tooth ratio defined between the teeth of the drive sprocket and the teeth of the lift sprocket.